September 28, 2011

A recent review of the HIV prevention trial Vaginal and Oral Interventions to Control the Epidemic (VOICE), conducted by an independent safety monitoring board, recommended that the Viread®  arm of the study be discontinued.  Although Viread®, an oral form of an antiretroviral called tenofovir, was effective in preventing HIV infection in a study earlier this year called Partners PrEP, it did not demonstrate effectiveness in the VOICE trial.

No safety concerns were identified and importantly, the other arms of the study will continue without change.  In addition to Viread®, VOICE is testing the safety and effectiveness of taking a daily oral tablet of Truvada®, a combination of tenofovir and emtricitabine, and a daily dose of the vaginal gel formulation of tenofovir, as well as two corresponding placebo arms.

The review was conducted by the National Institute of Allergy and Infectious Diseases (NIAID)’s independent Prevention Trials Data and Safety Monitoring Board (DSMB), and the trial is being conducted by the Microbicide Trials Network (MTN). VOICE involves 5,029 women at 15 trial sites in Uganda, South Africa and Zimbabwe.

While it is disappointing that Viread®  did not work in this study group, we do not see this as a step back, but as a step forward down the path toward HIV prevention.  Each trial provides additional data that are used to answer important questions, and of course, new questions are formed as well.  We recognize not only the importance of collecting scientific evidence, but also of acquiring a better understanding of behavioral issues as well—the only effective methods of HIV prevention and contraception are the ones that women and men will use consistently.  While we aim to develop methods of prevention that do not rely on adherence, such as IUDs, implants, etc., we also recognize the importance of choice.  VOICE is the first trial to evaluate both a pill and a gel, and we look forward to a final analysis that will shed more light on all of these important issues.

Final results from VOICE will be used to support regulatory approval for tenofovir gel.  CONRAD provided the gel to the VOICE trial and is leading the tenofovir gel regulatory process with the U.S. Food and Drug Administration and with the Medicines Control Council in South Africa. 

More information about the VOICE Study and related topics is available at  

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